This invention relates to a process for producing powders, and particularly metal powders, by electro-discharge machining.
Electro-discharge machining techniques have been used for many years to produce small diameter metallic powders. These prior art processes for creating powders involve immersing electrodes formed of the materials to be made into powder in an organic dielectric and by applying sufficient electrical energy to the electrodes while maintaining a gap between them to cause arcing, thereby eroding the electrodes and producing the powder. Typical dielectrics include kerosene, toluene, alcohol, benzenes, silicone oil and water. These organic dielectric fluids used in the machining process may react with the eroded materials in some way, such as by a chemical reaction, or by coating the individual particles.
It is sometimes desirable to produce uncontaminated powders or powders which have a desirable and unique microstructure. It is also desirable to produce powders that may be recovered and easily separated from the dielectric material.